A system for adjusting a trajectory of a projectile fired from a projectile launcher, for example a hand-held firearm or a mounted grappling hook launcher, may include a sight adapted to align a firing direction of the projectile launcher with a target. A range selector may be configured to adjust a vertical component (e.g., a direction along an axis parallel to a direction of gravity) of the firing direction in order to adjust an arc of the projectile toward the target. For example, a trajectory of a projectile fired from a launcher may change over time due to external forces such as gravity, friction (e.g., air resistance), etc. as the projectile travels toward the target. Accordingly, the range selector may be used to adjust a firing direction in order to arc the projectile more accurately towards the target.
One example approach of a system for adjusting a trajectory of a projectile is shown by Lee et al. in U.S. Pat. No. 8,407,924. Therein, a trajectory correcting unit is disclosed which may be fastened to a firearm via a gun barrel supporter. The trajectory correcting unit includes an optical sight mounted to a base of the unit, with an angle of the base (and therefore, the optical sight) relative to the firearm adjustable via a plurality of polygonal cams coupled to a rotary shaft. A stopper is fastened (e.g., by a bolt) to the trajectory correcting unit in order to lock a selected cam of the plurality of polygonal cams into engagement with a contact unit of the base. Each polygonal cam includes a plurality of surfaces configured to engage with the contact unit and to angle the base relative to the gun barrel supporter by different amounts. By angling the base relative to the gun barrel supporter, an angle of the optical sight relative to the firearm may be increased or decreased, and a trajectory of a projectile fired from the firearm may be adjusted.
However, the inventors herein have recognized potential issues with such systems. As one example, such systems may not be configured to adjust a trajectory of a projectile larger than a bullet, such as a grenade. Larger projectiles may have an increased mass relative to a bullet and may be fired at a lower relative velocity. The decreased velocity may result in an increased amount of time that the projectile is airborne, thereby increasing an amount of time that the projectile is subject to the external forces described above. This may result in a relatively large change in trajectory of the larger projectile when compared to a change in trajectory of a bullet. Accordingly, the polygonal cams described above may not provide a large enough angle between the optical sight and the firearm to arc the larger projectile towards a target.
As another example, while each cam of the plurality of polygonal cams may include a different arrangement and/or number of surfaces in order to adjust a trajectory for different conditions (e.g., with a different type of bullet, different elevation, etc.), an amount of time to switch between cams may be increased according to the trajectory correcting unit described above. For example, in order to switch from a first cam to a second cam, the stopper is unfastened from a first side of the trajectory correcting unit (e.g., by unfastening a fastening member coupled to the stopper, such as a bolt), the rotary shaft is moved to engage the second cam with the contact unit, and the stopper is re-fastened to a second (e.g., opposite) side of the trajectory correcting unit. Removing and replacing the stopper may increase an amount of time to change from the first cam to the second cam, and may additionally increase an amount of tools used to reposition the cams of the trajectory correcting unit (e.g., by utilizing a separate tool to remove the fastening member of the stopper).
In one example, the issues described above may be at least partially addressed by a method for an article of manufacture, comprising: a base having a cylindrical opening; a cartridge rotatably mounted in the cylindrical opening and having a quick-release element and a cam surface; and a pivoting sight mount surface engaging the cam surface. In this way, a quick selection between a plurality of cams is enabled in order to adjust a trajectory of a projectile without the use of tools.
As one example, the quick-release element includes an unlock button positioned at a first side of the cartridge, and the sight mount surface is additionally coupled to a bubble level in order to indicate a tilt amount of the sight mount surface. A second side of the cartridge, opposite to the first side, includes a plurality of cams positioned coaxially relative to each other and radially offset from a central axis of the cartridge. Each cam of the plurality of cams includes a single flat surface, and each cam includes a different, continuously curved surface coupled to the corresponding single flat surface. The engagement of the continuously curved surface of each cam with the sight mount surface defines an angle of the sight mount surface relative to the base. Adjusting an engagement position of the selected cam with the sight mount surface also adjusts an angle of a sight (e.g., an optical dot sight) coupled to the sight mount surface, and a trajectory of a projectile fired from a device (such as a grenade launcher) coupled to the article of manufacture (which may herein be referred to as a high-angle sight mount) may be corrected.
By utilizing the quick-release element of the cartridge, an operator of the high-angle sight mount may quickly remove and replace one cartridge including a first plurality of cams with another cartridge including a different, second plurality of cams. Each plurality of cams may be configured for a separate set of conditions, such as projectile type, environmental conditions, elevation, etc., enabling the operator to quickly respond to changes in conditions by changing cartridges without the use of tools (for example, changing from a cartridge with cams configured for one projectile type, to a cartridge with cams configured for a different projectile type). The operator may also choose which cam of the cartridge is in engagement with the sight mount surface by sliding the cartridge along the cartridge central axis within the cylindrical opening. In this way, a single cartridge may include cams configured for several conditions (such as those described above), enabling the operator to select an appropriate cam without disengaging the cartridge from the cylindrical opening and without using tools.
Additionally, by offsetting the position of each cam relative to the central axis of the cartridge, the selected cam may rotate the sight mount surface through an increased angular range. As a result, the angle of the optical sight relative to the base may be increased, thereby increasing an arcing distance of a projectile fired from a device to which the high-angle sight mount is mounted. In this way, the high-angle sight mount may adjust trajectories for an increased amount of projectile types, including projectiles larger than bullets. The bubble level may be configured to adjust for a spin drift of such a projectile (in one example, a grenade) due to external forces on the projectile (e.g., gravity, air resistance, etc.).
It should be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.
FIGS. 1-12 are shown to scale, though other relative dimensions may be used.